The invention relates to a reading light unit for a passenger service unit in an overhead panel above a number of passenger seats. Further the invention relates to a reading light system of a light control unit and a reading light unit of the mentioned kind.
Passenger service units of the aforementioned type are known in the state of the art and are widely used in civil aircrafts. Generally a passenger service unit comprises a reading light, a passenger air supply device, oxygen masks, warning lights and the like appliances. In some aircrafts one passenger service unit is provided for each seat of a passenger and crew member. In other aircrafts one single passenger service unit is provided for a number of the seats, e.g. in particular for a row of seats. A row usually is aligned crosswise to an alley of seats; a row may have two, three, four, five, six or more seats depending on the size of the civil aircraft. Modern civil aircrafts cabins may have a capacity of several hundred seats for passengers.
A reading light unit for a aforementioned passenger service unit is known to be provided with a light source for emitting light to a passenger seat. Usually an adjusted light source is provided in a containment from the manufacturer and is incorporated into a passenger service unit during assembly thereof; thus adjustment of the light source is not admitted. Usually, as assembled, the emission of light from the light source is such that a light beam is directed to a proper spot or illumination plane near the passenger seat. A directional adjustment of the light source, however, may be convenient to vary depending on the situation of the passenger during the flight. The passenger might be in the situation to have a meal served or might be in the situation to read papers or might be in the situation to sleep. Already the above mentioned situations usually can demand for an adjusted reading light. Up to now a light source can be switched off or on manually. It is desirable to provide a more convenient adjustment of a light source.